If you keep a copy of the O.P.H. (that's Lisa Birnbach's 1980 classic, The Official Preppy Handbook) on your bedside table, you knew just what that title meant. Preppy style is always timeless and in style, because it is basically unchanging. The classic good taste and clean lines of preppy style make it a natural for a any wedding.
Certain colors have a strong association with preppy style, especially the pink and green combo. Tiffany blue and sunshine yellow also work, and for a more sophisticated look,try pink, green, or blue paired with chocolate brown accents. You can carry these colors throughout everything: invitations (Engraved or letterpress, please. Bonus points for monograms.), flowers, table décor, bridesmaids' dresses, and even signature cocktails. (For more on preppy drinking, you must check out a fabulous book called Tipsy in Madras.)
There are variations on the preppy theme that you can use for your reception. There is the aforementioned pink and green, of course, but you could also choose to decorate with sun-washed Madras plaid, or a breezy oceanside Nantucket look. Your décor should not be overly fussy or ornate. Instead of towering floral centerpieces surrounded by votives, think blue hydrangea in a galvanized bucket with grosgrain ribbons ties around it. For an informal reception, gerbera daisies in shades of pink would strike just the right note. Roses in white or the palest pink would be beautiful for a more formal preppy wedding.

Of course at any wedding, it is the bride's dress that sets the tone. For a preppy wedding, the bridal gown should be simple with clean lines (like an A-line strapless dress). Appropriate fabrics would include silk shantung, silk organza, or silk mikado. For a summer wedding, a custom gown in white-on-white seersucker or a pique would be amazing. The bridesmaids' dresses would also be great in organza or shantung for a more formal wedding, or for an informal look, you can't beat a Lilly Pulitzer dress. The bride may wish to pull the color of her attendants' dresses into her own gown, often as a sash at the waist.
Accessories should be classic and timeless, so pearl jewelry is perfect. The bride will likely choose to wear a classic strand of pearls (a wonderful wedding gift from her fiancee or father), and pearl bridesmaid jewelry will also be the right look for her attendants. If your wedding is more formal, the bridesmaids will likely wear pearl strands like the bride. For a less formal outdoor wedding, tin cup style necklaces would be a great choice for pearl bridesmaid jewelry (they make a sweet gift from the bride). And because preppy girls love anything monogrammed, present your bridesmaids their gifts in personalized little silver boxes.
We shouldn't forget the men; preppy guys also have a distinctive style. A formal wedding could call for classic black tie, but for a daytime ceremony, it would look terrific for the men to wear navy blazers with khakis. For the perfect finishing touch, coordinate the neckties to the bridesmaids' dresses, or choose ties with a great preppy motif like whales or sailboats (anything from Vineyard Vines would work). There are also regional variations on mens' attire, such as Nantucket red pants for a wedding on that island.

It is the little fun touches that will set your preppy style wedding apart. You could go all out, and have a Lilly Pulitzer pattern done on your wedding cake. Instead of numbering the tables at the reception, name them after preppy places like Palm Beach, Greenwich, or Bar Harbor. A game of croquet on the lawn would also be a neat reception idea. Most of all, remember to enjoy your wedding, because if there is one thing preppies love, it's a great party!